The invention relates to a high-voltage generator for applying a high-voltage discharge current to a discharge unit.
A high-voltage generator of this kind can be used, for example for producing an electric discharge in a discharge chamber (the discharge unit) in order to produce ozone. During such a process a high-voltage generator causes a corona discharge in atmospheric air, so that ozone is formed from the atmospheric oxygen. The corona discharge is caused by the high-voltage generator applying a high voltage between two electrodes in the discharge chamber. The electrodes are separated from one another by a high-voltage insulator which also acts as a dielectric. Atmospheric air is present in the space between the electrodes. The high voltage is controlled to a value such that it does not yet cause high-voltage breakdown but a corona discharge which forms ozone from the oxygen present in the atmospheric air.
Because atmospheric air is treated in the discharge chamber, the condition of this air (i.e. the pressure, temperature, humidity and impurities) will vary comparatively strongly from one instant to another. As a result, it may occur that at a voltage for which initially only a corona discharge occurred an electric breakdown occurs due to the changed atmospheric conditions. This electric breakdown affects the surface of the high-voltage insulator in the discharge chamber, thus degrading its insulating properties. After a large number of electric breakdowns, the high-voltage insulator loses its insulating effect so that the high voltage for generating the corona discharge can no longer be sustained and the high-voltage insulator has to be replaced after a comparatively short period of time.